Heat index QUESTION

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JCcares
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Heat index QUESTION

Post by JCcares »

When your weather is 37c 98 F sunny if one has the option is it best care for cacti to keep them in the shade?

I’m a little confused when I think about there nature habitats where the heat exceeds 40c and there is no shade in sight.

Thank you.
My name is Joe I Live in Hickory NC USA four equal perfect seasons.
TheORKINMan
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Re: Heat index QUESTION

Post by TheORKINMan »

I suspect this is highly dependent on the species. A Patagonian highlands cactus will likely need shade. A cactus from central Mexico probably will be fine.
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JCcares
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Re: Heat index QUESTION

Post by JCcares »

TheORKINMan wrote: Wed Jun 15, 2022 12:38 pm I suspect this is highly dependent on the species. A Patagonian highlands cactus will likely need shade. A cactus from central Mexico probably will be fine.
Thank you 🙏🏽 I guess if I’m going to error it won’t hurt them give them some shade those 2 days.
My name is Joe I Live in Hickory NC USA four equal perfect seasons.
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MrXeric
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Re: Heat index QUESTION

Post by MrXeric »

It does depend on species, but I would argue many can be acclimated to higher temperatures than they encounter in the wild. If your plants have been well acclimated to high temperatures, they should fare well in direct sun, otherwise do shade them.
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greenknight
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Re: Heat index QUESTION

Post by greenknight »

Plants in habitat are in the ground, the roots don't get that hot. Pots that are getting hit by the sun can get very hot, especially dark-colored pots, there's a danger of cooking the roots of a potted cactus. You need to take this into consideration as well.

Where you have a lot of pots standing close together, obviously only the ones on the side are getting sun hitting the side of the pots. A board on edge along the south side to shade those pot sides would protect that group. Anywhere you have a bunch of pots in a row you could use a similar strategy. Another method is to place pots inside larger pots big enough so there's an air space around them. However you do it, protecting the roots from getting overheated will save your cacti from a lot of stress when it gets hot.
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JCcares
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Re: Heat index QUESTION

Post by JCcares »

greenknight wrote: Thu Jun 16, 2022 5:28 am Plants in habitat are in the ground, the roots don't get that hot. Pots that are getting hit by the sun can get very hot, especially dark-colored pots, there's a danger of cooking the roots of a potted cactus. You need to take this into consideration as well.

Where you have a lot of pots standing close together, obviously only the ones on the side are getting sun hitting the side of the pots. A board on edge along the south side to shade those pot sides would protect that group. Anywhere you have a bunch of pots in a row you could use a similar strategy. Another method is to place pots inside larger pots big enough so there's an air space around them. However you do it, protecting the roots from getting overheated will save your cacti from a lot of stress when it gets hot.
Great idea Spencer!!! Thank you!! I would never have thought of all that.
My name is Joe I Live in Hickory NC USA four equal perfect seasons.
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greenknight
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Re: Heat index QUESTION

Post by greenknight »

Wish I could take credit for it, Joe, but it hadn't occurred to me either until I started following this forum - those are ideas I picked up here. Roots of plants in the ground aren't subjected to as much heat or cold as the tops are, so they aren't as adapted for extreme temperatures. Even hot climate cacti will suffer if the roots get overheated, cold-hardy cacti can be killed if the roots get frozen too hard.
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7george
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Re: Heat index QUESTION

Post by 7george »

greenknight wrote: Tue Jun 21, 2022 2:20 am Wish I could take credit for it, Joe, but it hadn't occurred to me either until I started following this forum - those are ideas I picked up here. Roots of plants in the ground aren't subjected to as much heat or cold as the tops are, so they aren't as adapted for extreme temperatures. Even hot climate cacti will suffer if the roots get overheated, cold-hardy cacti can be killed if the roots get frozen too hard.
Absolutely right. Potted cacti cannot avoid heat burying themselves into the ground. Columnars (esp. grown-up) easily accept full sun being adapted to open areas, not to the shade. Small globular cacti need more shade growing under shrubs or near rocks or bigger cacti in their habitats. Also seasonal moving of potted cacti in/out, rotations makes them harder to adapt to full sun at high heat times.
If your cacti mess in your job just forget about the job.
°C = (°F - 32)/1.8
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nachtkrabb
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Re: Heat index QUESTION

Post by nachtkrabb »

Hallo folks,

loads of interesting ideas. I have some plants, some Mammillarias & others, that really do need the hottest & sunniest place I can find for them, and others that really prefer to stay outside but in the shade as Gymno horstii buenekeri.
I thus have a table which plants tolerate which temperatures & how much sun according to information from books & from the internet, especially llifle. Often I guess according to where the plants come from (climate zone, altitude etc.) and how they naturally grow (in the open or under bushes, etc).
Most plants get more or less the same summer place each year. But with some I experiment until I find out what suits them best.

I think it is very important after a winter indoors (especially when at dark places) to get them used to unfiltered sunlight and UV-rays slowly. They get sunburns just as we do. So I place them at a semi-shade place for a couple of days before moving them into the scorching sun (if they like scorching sun).
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7george
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Re: Heat index QUESTION

Post by 7george »

Lot of ecotypes among cacti. Mamms and other mexicans enjoy high heat and grow better and faster in midsummer but would like high day-night contrasts so cool outside placement with some shade is perfect. Mountain southamerican species, many Notocactus go dormant at high heat. Chileans also grow well if cool nights follow hot days. But it depends on altitude of origin habitats. Tropicals go weel if not too cold but also don't like constant high heat. No common fixed heat index for all.
If your cacti mess in your job just forget about the job.
°C = (°F - 32)/1.8
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JCcares
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Re: Heat index QUESTION

Post by JCcares »

7george wrote: Tue Aug 16, 2022 3:09 am Lot of ecotypes among cacti. Mamms and other mexicans enjoy high heat and grow better and faster in midsummer but would like high day-night contrasts so cool outside placement with some shade is perfect. Mountain southamerican species, many Notocactus go dormant at high heat. Chileans also grow well if cool nights follow hot days. But it depends on altitude of origin habitats. Tropicals go weel if not too cold but also don't like constant high heat. No common fixed heat index for all.
Makes sense 7george thank you 🙏🏽
My name is Joe I Live in Hickory NC USA four equal perfect seasons.
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